A certain cynical man went to the house of Rabbi Hillel, and said mockingly, “Your Torah, your wonderful Torah! I will become your student if you can teach it to me while I stand on one foot.”

Now Rabbi Hillel knew that the man was mocking his tradition, as there is never an end to the study of the Torah, but he said, “Very well, I shall teach you the whole Torah, and I will do so while I also stand on one foot!” So the Rabbi stood on one foot and said, “This is our Holy Torah: What is hateful to you, do not do unto others.”

Then he put his foot down and looked directly at the man, and said, “That is the meaning of the whole Torah. All the rest is commentary.” The man instantly became a disciple of the great Rabbi.